Auto merge of #127311 - oli-obk:do_not_count_errors, r=<try>

Avoid follow-up errors and ICEs after missing lifetime errors on data structures

Tuple struct constructors are functions, so when we call them typeck will use the signature tuple struct constructor function to provide type hints. Since typeck mostly ignores and erases lifetimes, we end up never seeing the error lifetime in writeback, thus not tainting the typeck result.

Now, we eagerly taint typeck results by tainting from `resolve_vars_if_possible`, which is called all over the place.

I did not carry over all the `crashes` test suite tests, as they are really all the same cause (missing or unknown lifetime names in tuple struct definitions or generic arg lists).

fixes #124262
fixes #124083
fixes #125155
fixes #125888
fixes #125992
fixes #126666
fixes #126648
fixes #127268

Author: bors

compiler/rustc_infer/src/infer/mod.rs

@@ -1273,6 +1273,9 @@ impl<'tcx> InferCtxt<'tcx> {
     where
         T: TypeFoldable<TyCtxt<'tcx>>,
     {
+        if let Err(guar) = value.error_reported() {
+            self.set_tainted_by_errors(guar);
+        }
         if !value.has_non_region_infer() {
             return value;
         }

tests/crashes/124083.rs

@@ -4,7 +4,6 @@ pub struct Foo<'a, 'b, T> {
     field1: dyn Bar<'a, 'b>,
     //~^ ERROR
     //~| ERROR
-    //~| ERROR
 }
 
 pub trait Bar<'x, 's, U>

tests/crashes/124262.rs

@@ -5,7 +5,7 @@ LL |     field1: dyn Bar<'a, 'b>,
    |                 ^^^ expected 1 generic argument
    |
 note: trait defined here, with 1 generic parameter: `U`
-  --> $DIR/unable-fulfill-trait.rs:10:11
+  --> $DIR/unable-fulfill-trait.rs:9:11
    |
 LL | pub trait Bar<'x, 's, U>
    |           ^^^         -
@@ -20,24 +20,7 @@ error[E0227]: ambiguous lifetime bound, explicit lifetime bound required
 LL |     field1: dyn Bar<'a, 'b>,
    |             ^^^^^^^^^^^^^^^
 
-error[E0478]: lifetime bound not satisfied
-  --> $DIR/unable-fulfill-trait.rs:4:13
-   |
-LL |     field1: dyn Bar<'a, 'b>,
-   |             ^^^^^^^^^^^^^^^
-   |
-note: lifetime parameter instantiated with the lifetime `'b` as defined here
-  --> $DIR/unable-fulfill-trait.rs:3:20
-   |
-LL | pub struct Foo<'a, 'b, T> {
-   |                    ^^
-note: but lifetime parameter must outlive the lifetime `'a` as defined here
-  --> $DIR/unable-fulfill-trait.rs:3:16
-   |
-LL | pub struct Foo<'a, 'b, T> {
-   |                ^^
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0107, E0227, E0478.
+Some errors have detailed explanations: E0107, E0227.
 For more information about an error, try `rustc --explain E0107`.